1. Field of the Invention
This invention relates to a plasma deposition device, more particularly to a plasma deposition device that can produce plasma evenly.
2. Description of the Related Art
With the rapid growth of high-tech industry, a plasma enhanced chemical vapor deposition (PECVD) technology has gained much attention and is widely applied, especially in the field of semiconductor fabrication. For example, in a process for forming a polysilicon film in a thin film transistor liquid crystal display (TFT-LCD), or in a process for forming a wafer substrate and a solar energy plate in a solar cell, it is necessary to use a PECVD device.
However, PECVD may have the following problem. After a silicon film forming-material, such as silane (SiH4), reacts with the plasma to release silicon ions used to form a silicon film on a substrate, the silicon film is not only formed on the substrate, but also accumulates on a gas supplying conduit, clogging transmission of microwave. When accumulation is serious, no plasma will be generated, and replacement of the gas supplying conduit needs to be conducted. This will increase the cost for processing a semiconductor film.